I understand that this is frustrating.
To gather some context, could you tell me a little bit more about what you were doing at the time of getting the error? For example, what section of the admin were you in?
This particular error may have come about as a potential browser cache issue, so as a troubleshooting step I would first recommend you try to clear the cache and cookies on your Google Chrome browser following these steps here. After, please try to replicate what you were doing and see if the error occurs again.
If clearing the cache does not help, the next thing to do is to try using an alternative device. For example, if you were using a mobile device at the time the error occurred, try again using a desktop.
The last thing you could try on your end for troubleshooting is to reset your internet as that might also be influencing this error.
Finally, if none of the above helps, please take a screenshot of the error that you're getting and get in touch with us through our support here so that we can take a closer look at this for you. The reason that I am redirecting you is because at the moment, we are unable to access your account details via the Shopify Community. You can also send a link of this thread when you're in touch with our support just so they already have an idea of the troubleshooting steps that you have tried so far - it will help save time and get to the bottom of your issue quicker.
On a side note, I am seeing that this is your first post here - welcome to the Community! Are you just getting started with Shopify as well? If so, you should definitely take a look at our Shopify Blog article on How to Start an Online Store - it is very step by step and will help you find your footing in the beginning of your journey with Shopify.
If you have any further questions, please also feel free to get back to me here.
Thank you for the nice welcome and for giving me tips on how to solve this issue. This often happens when I am working on products, like adding variants to a product. I have been on Shopify for several years now and have never had this issue until several months ago. I will try the tips you have suggested and see if it makes a difference.